Crimp terminations for conductors in implantable medical lead and method of making same

ABSTRACT

A method of manufacturing an implantable medical lead is disclosed herein. The method may include: providing a lead body including a proximal end, a distal end, and an electrode near the distal end; provide a conductor extending between the proximal and distal ends; providing a crimp including a ribbon-like member and extending the ribbon-like member around the conductor; and mechanically and electrically connecting the ribbon-like member to the electrode.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.12/716,552, filed Mar. 3, 2010, now U.S. Pat. No. 8,594,761, and relatedto:

1) Ser. No. 14/051,764, titled “Crimp Terminations for Conductors inImplantable Medical Lead and Method of Making Same”;

2) Ser. No. 14/051,795, titled “Crimp Terminations for Conductors inImplantable Medical Lead and Method of Making Same”;

3) Ser. No. 14/051,850, titled “Crimp Terminations for Conductors inImplantable Medical Lead and Method of Making Same”;

4) Ser. No. 14/051,877, titled “Crimp Terminations for Conductors inImplantable Medical Lead and Method of Making Same”;

5) Ser. No. 14/051,976, titled “Crimp Terminations for Conductors inImplantable Medical Lead and Method of Making Same”;

6) Ser. No. 14/051,995, titled “Crimp Terminations for Conductors inImplantable Medical Lead and Method of Making Same”;

7) Ser. No. 14/052,020, titled “Crimp Terminations for Conductors inImplantable Medical Lead and Method of Making Same”;

8) Ser. No. 14/052,042, titled “Crimp Terminations for Conductors inImplantable Medical Lead and Method of Making Same”;

all applications filed Oct. 11, 2014.

FIELD OF THE INVENTION

The present invention relates to medical apparatus and methods. Morespecifically, the present invention relates to implantable medical leadsand methods of manufacturing such leads.

BACKGROUND OF THE INVENTION

Implantable pulse generators, such as pacemakers, defibrillators,implantable cardioverter defibrillators (“ICD”) and neurostimulators,provide electrotherapy via implantable medical leads to nerves, such asthose nerves found in cardiac tissue, the spinal column, the brain, etc.Electrotherapy is provided in the form of electrical signals, which aregenerated in the pulse generator and travel via the lead's conductors tothe electrotherapy treatment site.

Patients may benefit from electrotherapy treatments to be proposed inthe future. However, current conventional lead manufacturing technologyhas generally limited the extent to which leads can be reduced in sizeand the elements or features that can be carried on leads.

There is a need in the art for a lead having a configuration that allowsthe lead to have a reduced size and which is capable of supportingelements or features in a variety of configurations. There is also aneed in the art for a method of manufacturing such a lead.

BRIEF SUMMARY OF THE INVENTION

Disclosed herein is an implantable medical lead. In one embodiment, thelead may include a longitudinally extending body, a helical anchor and alead connector end. The longitudinally extending body may include adistal end, a proximal end, a braid-reinforced inner tubular layerextending between the proximal and distal ends, and an outer tubularlayer extending between the proximal and distal ends. Thebraid-reinforced inner tubular layer may extend through the outertubular layer in a coaxial arrangement. The helical anchor electrode maybe operably coupled to a distal end of the braid-reinforced innertubular layer. The lead connector end may be operably coupled to theproximal end of the body and include a pin contact operably coupled to aproximal end of the braid-reinforced tubular layer. Rotation of the pincontact relative to the lead connector end may cause rotation of thebraid-reinforced inner tubular layer within the outer tubular layer, andthe resulting rotation of the braid-reinforced inner tubular layer maycause rotation of the helical anchor electrode.

Another implantable medical lead is also disclosed herein. In oneembodiment, the lead includes a longitudinally extending body having adistal end, a proximal end, and a braid-reinforced tubular layerextending between the proximal and distal ends. The braid-reinforcedtubular layer may include a braid arrangement imbedded in a polymer wallmaterial. The braid arrangement may include first and second conductorsand first and second ribbons. The conductors and ribbons may behelically cross wound with each other such that the conductors do notcross each other and the ribbons do not cross each other.

Also disclosed herein is a method of assembling an implantable medicallead. In one embodiment, the method includes: providing a firstlongitudinally extending tubular liner including an outercircumferential surface; providing a first braid arrangement over theouter circumferential surface of the first longitudinally extendingtubular liner, wherein the first braid arrangement includes first andsecond conductors and first and second ribbons, wherein the conductorsand ribbons of the first braid arrangement are helically cross woundwith each other such that the conductors do not cross each other and theribbons do not cross each other; reflowing or molding (e.g., liquidinjection mold (“LIM”)) a first polymer material over the first braidarrangement and outer circumferential surface of the firstlongitudinally extending tubular liner such that the braid arrangementis substantially imbedded in the polymer material and the polymermaterial substantially adheres to the outer circumferential surface,resulting in a first braid-reinforced tubular layer; and electricallyconnecting the first conductor to an electrode.

Another implantable medical lead is also disclosed herein. In oneembodiment, the lead includes a longitudinally extending body includinga distal end and a proximal end, an electrode on the body near thedistal end, a lead connector end operably coupled to the proximal end ofthe body, an electrical conductor extending between the lead connectorend and the electrode, and a crimp including a collar and a tailextending from the collar. The collar includes a hole. The tail extendsaround the electrical conductor and through the hole. The crimp iselectrically and mechanically coupled to the electrode.

Yet another implantable medical lead is disclosed herein. In oneembodiment, the lead includes a longitudinally extending body includinga distal end and a proximal end, an electrode on the body near thedistal end, a lead connector end operably coupled to the proximal end ofthe body, an electrical conductor extending between the lead connectorend and the electrode, and a crimp. The crimp includes opposed first andsecond portions that are each generally shaped like a half-cylinder. Theportions are joined along a common longitudinal side. A tail extendsfrom a free longitudinal side of the first portion. A hole is defined inthe second portion. The tail extends around the electrical conductor andthrough the hole. The crimp is electrically and mechanically coupled tothe electrode.

Yet another implantable medical lead is disclosed herein. In oneembodiment, the lead includes a longitudinally extending body includinga distal end and a proximal end, an electrode on the body near thedistal end, a lead connector end operably coupled to the proximal end ofthe body, an electrical conductor extending between the lead connectorend and the electrode, and a crimp. The crimp includes a ribbon having afirst end and a second end. The ribbon extends around the conductor. Afirst length of the ribbon near the first end is in contact with asecond length of the ribbon near the second end. The crimp iselectrically and mechanically coupled to the electrode.

Another implantable medical lead is disclosed herein. In one embodiment,the lead includes a longitudinally extending body including a distal endand a proximal end, an electrode on the body near the distal end, a leadconnector end operably coupled to the proximal end of the body, anelectrical conductor extending between the lead connector end and theelectrode, and a crimp. The crimp includes a portion and a tailextending from the portion, the portion having a generally half-cylindershape that defines a trough. The conductor is received in the trough.The tail is electrically and mechanically coupled to the electrode.

Another implantable medical lead is disclosed herein. In one embodiment,the lead includes a longitudinally extending body including a distal endand a proximal end, an electrode on the body near the distal end, a leadconnector end operably coupled to the proximal end of the body, anelectrical conductor extending between the lead connector end and theelectrode, and a crimp. The crimp includes a generally cylindricalshape, a split extending generally longitudinally along the generallycylindrical shape, a hole in the generally cylindrical shape oppositethe split, and a trough in which the conductor is received. The crimp iselectrically and mechanically coupled to the electrode.

Yet another implantable medical lead is disclosed herein. In oneembodiment, the lead includes a longitudinally extending body includinga distal end and a proximal end, an electrode on the body near thedistal end, a lead connector end operably coupled to the proximal end ofthe body, an electrical conductor extending between the lead connectorend and the electrode, and a crimp. The crimp includes a spherical outersurface and a recess formed in the spherical outer surface. Theconductor is received in the recess, the crimp electrically andmechanically coupled to the electrode.

Yet another implantable medical lead is disclosed herein. In oneembodiment, the lead includes a longitudinally extending body includinga distal end and a proximal end, an electrode on the body near thedistal end, a lead connector end operably coupled to the proximal end ofthe body, an electrical conductor extending between the lead connectorend and the electrode, and a crimp. The crimp includes a cylindricalouter surface, a pair of recesses formed in the cylindrical outersurface, and another recess formed in an end of the crimp. The conductoris received in the another recess, and the crimp is electrically andmechanically coupled to the electrode.

Another implantable medical lead is disclosed herein. In one embodiment,the lead includes a longitudinally extending body including a distal endand a proximal end, an electrode on the body near the distal end, a leadconnector end operably coupled to the proximal end of the body, anelectrical conductor extending between the lead connector end and theelectrode, and a crimp. The crimp includes a helical shaped outersurface and a helically shaped opening extending through the length ofthe crimp. The conductor extends through the helically shaped opening.The crimp is electrically and mechanically coupled to the electrode.

Yet another implantable medical lead is disclosed herein. In oneembodiment, the lead includes a longitudinally extending body includinga distal end and a proximal end, a ring electrode on the body near thedistal end, a lead connector end operably coupled to the proximal end ofthe body, an electrical conductor extending between the lead connectorend and the electrode, and a crimp electrically and mechanically coupledto the electrode. The ring electrode includes a cylindrical wall and aseam extending proximal to distal along the wall. The seam is formed bya first wall edge extending proximal to distal and a second wall edgeextending proximal to distal. The wall edges are opposed and broughttogether to form the seam. Each wall edge includes a notch such that,when the wall edges are brought together to form the seam, the notchesform a window extending through the wall.

A method of manufacturing an implantable medical lead is also disclosedherein. In one embodiment the method includes: providing a lead bodyincluding a proximal end, a distal end, and an electrode near the distalend; provide a conductor extending between the proximal and distal ends;providing a crimp including a ribbon-like member and extending theribbon-like member around the conductor; and mechanically andelectrically connecting the ribbon-like member to the electrode.

Yet another method of manufacturing an implantable medical lead isdisclosed herein. In one embodiment the method includes: providing alead body including a proximal end and a distal end; providing aconductor extending between the proximal and distal ends; ablating aringed recess in an outer surface of the lead body; providing a splitring electrode; threading the lead body through the split ring electrodewhen the split ring electrode is expanded; positioning the split ringelectrode in the ringed recess; and mechanically and electricallyconnecting the ring electrode to the conductor.

A method of manufacturing an implantable medical lead is also disclosedherein. In one embodiment the method includes: providing a lead bodyincluding a proximal end, a distal end, and an electrode near the distalend; provide a conductor extending between the proximal and distal ends,the conductor including a helical crimp mounted on the conductor, theconductor extending through the helical crimp; and mechanically andelectrically connecting the helical crimp to the electrode.

While multiple embodiments are disclosed, still other embodiments of thepresent invention will become apparent to those skilled in the art fromthe following Detailed Description, which shows and describesillustrative embodiments of the invention. As will be realized, theinvention is capable of modifications in various aspects, all withoutdeparting from the spirit and scope of the present invention.Accordingly, the drawings and detailed description are to be regarded asillustrative in nature and not restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of an implantable medical lead and a pulsegenerator for connection thereto.

FIG. 2 is an isometric view of a distal portion of a tubular body of amedical lead similar to the lead depicted in FIG. 1, except the leadhaving an active fixation helical anchor at the lead distal end.

FIG. 3 is an enlarged isometric view of the distal portion of thetubular body of the medical lead of FIG. 2, except the shock coil ishidden and the outer circumferential surface of the outer tubular layerof the lead body is shown in phantom line for clarity purposes.

FIG. 4 is a transverse cross section of the tubular body of the medicallead as taken along section line 4-4 in FIG. 3.

FIG. 5 is a side view of an example conductor/fiber braid arrangementthat may be in at least one of the tubular layers or walls forming thetubular body of FIG. 3.

FIG. 6 is an isometric view of the conductor/fiber braid arrangement ofFIG. 5.

FIG. 7 is the same view as FIG. 5, except the conductor/fiber braidarrangement has been reflowed or molded with SPC to form a braidedtubular wall or layer of the tubular body depicted in FIGS. 3 and 4.

FIG. 8 is an enlarged partial transverse cross section through a windowformed in the outer tubular wall or layer at arrow A and as taken alongsection line 8-8 in FIG. 3.

FIG. 9 is the same view of the tubular body of the medical lead depictedin FIG. 3, except depicting only the inner tubular wall or layer andhelical anchor extending therefrom.

FIG. 10 is a longitudinal cross section of the inner tubular wall orlayer as taken along section line 10-10 in FIG. 9.

FIG. 11 is the same view as depicted in FIG. 10, except showing bothlayer assemblies.

FIG. 11A is an isometric view of a zip tie type crimp slug.

FIGS. 11B and 11C are, respectively, plan and side views of the crimpslug of FIG. 11A.

FIG. 12A is a plan view of a portion of a lead tubular body with aconductor helically routed about a liner layer and imbedded in thepolymer material, the helically routed conductor and polymer materialforming the reinforced layer.

FIGS. 12B and 12C are, respectively, cross sections of the lead tubularbody as taken along section line 12B-12B and section line 12C-12C inFIG. 12A.

FIG. 13A is a view of the tubular body similar to the view depicted inFIG. 12A.

FIG. 13B is generally the same view of the tubular body depicted in FIG.13A.

FIG. 13C is a side view of the lead body with the crimp fully cincheddown on the conductor.

FIG. 13D is an isometric view of the crimp fully cinched down on theconductor, which is shown in phantom lines.

FIG. 13E is another isometric view of the crimp fully cinched down onthe conductor, which is shown in phantom lines.

FIG. 14A is an isometric view of a split ring electrode in an expandedor split condition.

FIG. 14B is a view of a tubular body with the split ring electrodedepicted in FIG. 14A in a non-expanded condition.

FIG. 14C is a view of the tubular body with a weld formed at a crimp ofthe split ring electrode depicted in FIG. 14A.

FIG. 15A is an isometric of a notched ring electrode.

FIG. 15B is a view of the tubular body similar to that of FIG. 14B.

FIG. 16A is a plan view of another zip tie type crimp slug in a flatpattern condition.

FIG. 16B is an isometric view of the zip tie type crimp slug of FIG. 16Ain a formed state.

FIGS. 16C and 16D are, respectively, isometric and side views of thecrimp slug of FIG. 16B in a looped condition.

FIGS. 17A and 17B are, respectively, isometric and plan views of a leadbody.

FIG. 17C is a transverse cross section of the lead body at a location ofan alternative version of the ribbon equipped crimp of FIGS. 17A-17B.

FIG. 18A is an isometric view of another embodiment of the crimp slug.

FIGS. 18B and 18C are, respectively, top and bottom isometric views of ahalf-cylinder shaped tool for use in crimping the crimp on an exposedconductor.

FIG. 19 is an isometric view of a side loader crimp slug.

FIGS. 20A and 20B are, respectively, isometric and side views of anotched cylindrical crimp slug.

FIG. 20C is a side view of a portion of a lead, wherein the crimp slugof FIGS. 20A and 20B is coupled to a conductor.

FIGS. 21A and 21B, which are, respectively, isometric and side views ofa notched spherical crimp slug.

FIG. 22 is a plan view of a twisted micro wire crimp on a conductor.

FIGS. 23A and 23B are respectively, a side view of a lead body and anenlarged side view of the same lead body at a location of a crimp.

FIGS. 24A and 24B are, respectively, a plan view of a helical woundcrimp and a plan view of the same crimp mounted on a conductor.

FIGS. 25A-25C are, respectively, side, inner and outer views of ahelically shaped crimp.

FIGS. 25D-25E are, respectively, the crimp on a conductor and acrimp-equipped conductor assembled into a lead body, the conductor wouldbe fed through the helical crimp.

DETAILED DESCRIPTION

An implantable medical lead 10 is disclosed herein. In one embodiment,the implantable medical lead 10 includes a tubular body 50 having one,two or more tubular layers 125, 135 each reinforced with aconductor/fiber braid arrangement 115 imbedded in the polymer material162 forming the walls of the tubular layers 125, 135. Theconductor/fiber braid arrangement 115 may be one, two or more helicallywound conductors 100, 105, 110 woven with one, two or more helicallywound fiber strips 165. In one embodiment, the braid arrangement 115 issuch each conductor crosses the strips or ribbon 165, but does not crossitself or any other conductor. Similarly, each strip or ribbon 165crosses the conductors, but does not cross itself or any of the strip orribbon.

Such braid-reinforced layers 125, 135 offer the ability to manufacturelead bodies 50 have substantially reduced diameters, substantialimprovement with respect to torque and flexibility consistency andcapabilities, reduced manufacturing costs, and the ability to support alarge number of electrodes and sensors in a large variety ofconfigurations. Also, such braid-reinforced layers 135 may be used toreplace the common helically wound central coil as a mechanism forextending/retracting a helical anchor electrode 85 and, in doing so,offer an anchor extension/retraction mechanism that provides one-to-onetorque.

For a general discussion of an embodiment of a lead 10 including a bodyhaving at least one tubular layer reinforced with the conductor/fiberbraid arrangement, reference is made to FIG. 1, which is an isometricview of the implantable medical lead 10 and a pulse generator 15 forconnection thereto. The pulse generator 15 may be a pacemaker,defibrillator, ICD or neurostimulator. As indicated in FIG. 1, the pulsegenerator 15 may include a can 20, which may house the electricalcomponents of the pulse generator 15, and a header 25. The header may bemounted on the can 20 and may be configured to receive a lead connectorend 35 in a lead receiving receptacle 30.

As shown in FIG. 1, in one embodiment, the lead 10 may include aproximal end 40, a distal end 45 and a tubular body 50 extending betweenthe proximal and distal ends. The proximal end 40 may include a leadconnector end 35 including a pin contact 55, a first ring contact 60, asecond ring contact 61, which is optional, and sets of spaced-apartradially projecting seals 65. In some embodiments, the lead connectorend 35 may include the same or different seals and may include a greateror lesser number of contacts. For example, the lead connector end 35 maybe in the form of an IS-1, IS-4, DF-1, etc. configuration. The leadconnector end 35 may be received in a lead receiving receptacle 30 ofthe pulse generator 15 such that the seals 65 prevent the ingress ofbodily fluids into the respective receptacle 30 and the contacts 55, 60,61 electrically contact corresponding electrical terminals within therespective receptacle 30.

As illustrated in FIG. 1, in one embodiment, the lead distal end 45 mayinclude a distal tip 70, a tip electrode 75 and a ring electrode 80. Insome embodiments, as indicated in FIG. 2, which is an isometric view thedistal end 45 of an alternative embodiment of the lead 10, the leaddistal end 45 may include a helical anchor 85 that is extendable fromwithin the distal tip 70 for active fixation and may or may not act asan electrode. In other embodiments, the lead distal end 45 may includefeatures or a configuration that facilitates passive fixation.

As shown in FIGS. 1 and 2, in some embodiments, the distal end 45 mayinclude a defibrillation coil 82 about the outer circumference of thelead body 50. The defibrillation coil 82 may be located proximal of thering electrode 80.

As illustrated in FIG. 1 where the lead 10 is configured for passivefixation, the tip electrode 75 may form the distal tip 70 of the leadbody 50. The ring electrode 80 may extend about the outer circumferenceof the lead body 50, proximal of the distal tip 70. In otherembodiments, the distal end 45 may include a greater or lesser number ofelectrodes 75, 80 in different or similar configurations.

As indicated in FIG. 2 where the lead 10 is configured for activefixation, an atraumatic tip 90 may form the distal tip 70 of the leadbody 50, and the helical anchor electrode 85 may beextendable/retractable relative to the distal tip 70 through an opening95 in the distal tip 70. The ring electrode 80 may extend about theouter circumference of the lead body 50, proximal of the distal tip 70.In other embodiments, the distal end 45 may include a greater or lessernumber of electrodes in different or similar configurations.

In one embodiment, the tip electrode 75 or helical anchor electrode 85may be in electrical communication with the pin contact 55 via a firsthelically routed electrical conductor 100 (see FIGS. 9 and 10) and thering electrode 80 may be in electrical communication with the first ringcontact 60 via a second helically routed electrical conductor or pair ofhelically routed electrical conductors 105 (see FIGS. 2 and 3). In someembodiments, the defibrillation coil 82 may be in electricalcommunication with the second ring contact 61 via a third helicallyrouted electrical conductor or pair of helically routed electricalconductors 110 (see FIGS. 2, 3 and 8). In yet other embodiments, otherlead components (e.g., additional ring electrodes, various types ofsensors, etc.) mounted on the lead body distal region 45 or otherlocations on the lead body 50 may be in electrical communication with athird ring contact (not shown) similar to the second ring contact 61 viaa fourth helically routed electrical conductor or pair of helicallyrouted electrical conductors. Of course, if needed, helically routedelectrical conductors in addition to those already mentioned may berouted through the lead body in a manner similar to that depicted inFIGS. 2, 3, 9 and 10. Any of the helically routed conductors may berouted singly, in pairs, groups of three, groups of four, etc. Dependingon the embodiment, any of the helically routed electrical conductors maybe in the form of a multi-strand or filar cable or a solid wireconductor. Depending on the embodiment, any of the helically routedconductors may have a dedicated electrical insulation jacket or bejacketless such that the electrical conductor is reliant upon thematerial forming the tubular liner for electrical insulation.

For a detailed discussion regarding a lead body 50 employing theconductor/fiber braid arrangement 115 disclosed herein, reference ismade to FIGS. 3 and 4. FIG. 3 is an enlarged isometric view of thedistal end 45 of the tubular body 50 of the medical lead 10 of FIG. 2,except the shock coil 82 is hidden and the outer circumferential surface120 of the outer tubular layer 125 of the lead body 50 is shown inphantom line for clarity purposes. FIG. 4 is a transverse cross sectionof the lead body 50 as taken along section line 4-4 in FIG. 3.

As shown in FIG. 4, in one embodiment, the tubular body 50 of themedical lead 10 may include an innermost tubular liner layer 130, aninnermost tubular braid-reinforced layer 135, an outermost tubular linerlayer 140 and an outermost tubular braid-reinforced layer 125. An innercircumferential surface 145 of the innermost liner layer 130 may definea central lumen 150 extending longitudinally through the tubular leadbody 50. An outer circumferential surface of the innermost liner layer130 may abut against the inner circumferential surface of the innermostbraid-reinforced layer 135. An outer circumferential surface of theinnermost braid-reinforced layer 135 may displaceably abut against theinner circumferential surface of the outermost liner layer 135 such thatthe innermost layer assembly 155 (i.e., the innermost liner layer 130and the innermost braid-reinforced layer 135) may be caused torotationally displace within the outermost layer assembly 160 (i.e., theoutermost liner layer 140 and the outermost braid-reinforced layer 125).An outer circumferential surface of the outermost liner layer 140 mayabut against the inner circumferential surface of the outermostbraid-reinforced layer 125. The outer circumferential surface 120 of theoutermost braid-reinforced layer 125 may form the outer circumferentialsurface of the tubular lead body 120.

In one embodiment, the liner layers 130 and 140 may be formed ofpolytetrafluoroethylene PTFE or another polymer material having similarproperties. Each liner layer 130 and 140 may have a wall thickness ofbetween approximately 0.001″ and approximately 0.005″. In oneembodiment, the braid-reinforced layers 125 and 135 may each be formedof a conductor/fiber braid arrangement 115 (see FIGS. 3-10) imbedded ina wall material 162 of silicone rubber-polyurethane-copolymer (“SPC”),silicone rubber, polyurethane or another polymer material having similarproperties. Each layer 125 and 135 may have a wall thickness of betweenapproximately 0.004″ and approximately 0.02″.

In some embodiments, the layers 125 and 135 may both be braid-reinforcedwith the braid arrangement 115. However, in other embodiments, only oneof the layers 125 and 135 may be braid-reinforced with the braidarrangement 115, the other non-braid-reinforced layer being simply alayer of SPC or other similar polymer material. For example, in oneembodiment, the innermost layer 135 may be braid-reinforced with thebraid arrangement 115 and the outermost layer 125 may not employ thebraid arrangement 115. Conversely, in another embodiment, the outermostlayer 125 may be braid-reinforced with the braid arrangement 115 and theinnermost layer 135 may not employ the braid arrangement 115.

For a discussion of an example braid arrangement 115, reference is nowmade to FIGS. 5 and 6. FIG. 5 is a side view of the exampleconductor/fiber braid arrangement 115 that may be in at least one of thetubular layers or walls 125 and 135 forming the tubular body 50 of FIG.3. FIG. 6 is an isometric view of the conductor/fiber braid arrangement115 of FIG. 5.

As can be understood from FIGS. 5 and 6, the braid arrangement 115 maybe formed by braiding one, two or more single electrical conductors 100with one, two or more ribbons 165. In one embodiment, a ribbon 165 mayin the form of a fiberous polyester material. In other embodiments, aribbon 165 may be in the form of a non-fiberous polymer material. In oneembodiment, the ribbon 165 may be formed of polyester, nylon, KEVLAR™,expanded polytetrafluoroethylene (“ePTFE”) or etc. The ribbon 165 mayhave a thickness of less than approximately 0.0005 inch.

As can be understood from FIGS. 5 and 6, the braid arrangement 115 maybe wound in such a way that all the conductors 100 are spatiallyseparated from each other via the ribbon 165 and form a helical coilpattern in the braid arrangement 115. The braid pattern as depicted inFIGS. 3, 5 and 6 may be such that each conductor 100, 105, 110 onlycrosses over ribbons 165 and not other conductors, and each ribbon 165only crosses over the conductors, not other ribbons; thus, this braidpattern advantageously reduces the diameter of the braid arrangement 115as compared to braid patterns where each conductor crosses over otherconductors. The reduced diameter of the braid arrangement 115 disclosedherein saves space in the lead body 50.

Since the ribbon 165 acts as a spacer between the conductors 100,conductors 100 with or without individual electrical insulation jacketsmay be employed in the braid arrangement 115. As can be understood fromFIG. 7, which is the same view as FIG. 5, except the conductor/fiberbraid arrangement has been reflowed or molded (e.g., liquid injectionmold (“LIM”)) with SPC wall material 162 to form a braided tubular wallor layer 125 and 135 similar to those depicted in FIGS. 3, 4, 9 and 10.

As can be understood from FIGS. 3, 5 and 6, the braid pattern results inconductors 100, 105, 110 that are wound in an open pitch coil.Therefore, the conductors cannot touch each other and the resulting leadbody 50 has improved balance with respect to stresses in the lead body,reducing the likelihood of waviness in the lead body surface subsequentto manufacture. The braid arrangement 115 acts as a structural memberfor the final lead body construction. The braid arrangement 115 impartsto the lead body 50 many improved mechanical characteristics, includingimproved torqueability, pushability, flex fatigue resistance, and kinkresistance.

As can be understood from FIGS. 4-7, 9 and 10, in some embodiments, thebraid arrangement 115 may have one or any multiple number of electricalconductors 100, and these conductors 100 may be routed singly throughthe braid arrangement 115. In other embodiments, as can be understoodfrom FIGS. 3 and 4, the braid arrangement 115 may have one or anymultiple number of electrical conductors 105 and 110, and theseconductors 105 and 110 may be routed in pairs (as shown in FIGS. 3 and4), in groups of three, groups of four, or etc. through the braidarrangement 115.

The configuration of the braid-reinforced layers 125 and 135 readilylends itself to the efficient coupling of the electrical conductors 105and 110 to their respective electrodes 80 and 82. For example, as can beunderstood from FIG. 3 at arrow A, in one embodiment, the wall material162 of the outer reinforced layer 125 may be removed via laser ablation,mechanical cutting or other methods to form a window 170 through thewall material 162 that exposes the appropriate conductors 110.

As can be understood from FIG. 8, which is an enlarged partialtransverse cross section through the window 170 formed in the wallmaterial 162 of the outer tubular wall or layer 125 at arrow A and astaken along section line 8-8 in FIG. 3, a crimp slug 175 may extendthrough the window 170 between an electrode (e.g., the shock coil 82 inthis example) and the respective conductor pair 110. The bottom portion180 of the crimp slug 175 may be crimped to the conductors 110 and thetop portion 185 of the crimp slug 175 may be welded to the electrode 82.

As indicated in FIG. 8, the inner circumferential surface 190 of theoutermost reinforced layer 125 abuts against the outer circumferentialsurface 195 of the outermost liner layer 140. As the outermostreinforced layer 125 may be assembled on the outermost liner layer 140,the two layers 125 and 140 may be considered to be a single outermostassembly layer 160. The inner circumferential surface 200 of theoutermost liner layer 140 may displaceably abut against the outermostcircumferential surface 205 of the innermost braid-reinforced layer 135such that the innermost assembly layer 155 and outermost assembly layer160 may coaxially displace relative to each other once assembled intothe lead tubular body 50 and the outermost assembly layer 160 may bepulled over the innermost assembly layer 155 during the assembly of thelead tubular body 50.

Due to the innermost assembly layer 155 and outermost assembly layer 160being coaxially rotatably relative to each other, in some embodiments,the innermost assembly layer 155 may serve in place of the helicallycoiled central conductor commonly found in active fixation leads andwhich are commonly used to extend/retract the helical active fixationanchors of such leads. The configuration of the innermost assembly layer155 offers several advantages over the traditional helically coiledcentral conductor. For example, unlike the traditional helically coiledcentral conductor, the innermost assembly layer 155, due to itsconfiguration/construction, offers a one-to-one torque transfer whenused as the mechanism for extending/retracting the helical anchor 85.

A discussion of an embodiment of the lead tubular body 50 employing theinnermost assembly layer 155 as the mechanism for rotatablyextending/retracting the helical active fixation anchor 85 will now begiven with respect to FIGS. 9 and 10. FIG. 9 is the same view of thetubular body 50 of the medical lead 10 depicted in FIG. 3, exceptdepicting only the inner tubular wall or layer assembly 155 and helicalanchor 85 extending therefrom. FIG. 10 is a longitudinal cross sectionof the inner tubular wall or layer assembly 155 as taken along sectionline 10-10 in FIG. 9. As shown in FIGS. 9 and 10, wherein the wallmaterial 162 is shown in phantom line, the braid arrangement 115 may begenerally identical to that depicted in FIGS. 5-7.

As can be understood from FIG. 10, the inner circumferential surface 210of the innermost reinforced layer 135 abuts against the outercircumferential surface 215 of the innermost liner layer 130. As theinnermost reinforced layer 135 may be assembled on the innermost linerlayer 130, the two layers 135 and 130 may be considered to be a singleinnermost assembly layer 155. As discussed above, the outercircumferential surface 205 of the innermost braid-reinforced layer 135may displaceably abut against the innermost circumferential surface 200of the outermost liner layer 140 such that the innermost assembly layer155 and outermost assembly layer 160 may coaxially displace relative toeach other once assembled into the lead tubular body 50 and theoutermost assembly layer 160 may be pulled over the innermost assemblylayer 155 during the assembly of the lead tubular body 50.

As indicated in FIG. 10, a proximal end 220 of a metal helix shank 225may be received within the distal end of the innermost liner layer 130and coupled to the inner circumferential surface 155 of the layer 130. Adistal end 230 of the shank 225 may be received within and coupled tothe proximal end of the helical active fixation anchor 85. In a mannersimilar to that depicted in FIG. 8, the conductor 100 of the innermostreinforced layer 135 may be electrically coupled to the electricallyconductive shank 225, which is electrically coupled to the helicalanchor 85. Alternatively, in a manner similar to that depicted in FIG.8, the conductor 100 may be electrically coupled to the proximal end ofthe helical anchor 85.

As can be understood FIGS. 3, 9, 10, and 11, which is the same view asdepicted in FIG. 10, except showing both layer assemblies 155 and 160,because the helical anchor 85 is fixedly coupled to the distal end ofthe inner layer assembly 155 and the inner layer assembly 155 is capableof being displaced within the outer layer assembly 160, the helicalanchor can be caused to extend/retract relative to the lead distal tip70. More specifically, the extreme proximal end of the inner layerassembly 155 may be coupled to the pin contact 55 (see FIG. 1), whichmay be rotatable relative to the rest of the lead connector end 35 (seeFIG. 1). Rotation of the pin contact 55 in a first direction may causethe inner layer assembly 155 to axially rotate within the outer layerassembly 160 and longitudinally displace within the outer layer assembly160 such that the helical anchor 85 may be caused to extend distallyfrom the opening 95 in the distal tip 70. Rotation in an oppositedirection may cause the helical anchor 85 to retract back into theopening 95.

In one embodiment, the coupling of the shank 225 to the innermost linerlayer 130 in combination with the configuration of the header assembly235 (see FIG. 3) may be such that the helical anchor 85 is caused toextend/retract via rotation of the pin contact 55 despite the innerlayer assembly 155 being limited to axial rotation relative to the outerlayer assembly 160 and not being allowed to longitudinally displacewithin the outer layer assembly 160.

A variety of implantable medical leads 10 may be configured as describedherein. For example, the lead 10 may be a cardiac lead (both high andlow voltage), a multi-polar lead (both cardiac and neurologic), an MRIcompatible lead, and an “intelligent” lead such as those intelligentleads that incorporate active components, such as sensors, integratedcircuits, MEMS devices or drug delivery mechanisms.

The construction of a lead body 50 may be done on an individual basis oron a continuous basis. When the lead body 50 is manufactured on anindividual basis, the conductors 100, 105, 110 and ribbon 165 may bebraided together on a standard braiding machine to assemble the braidarrangement 115, which can then be stored on a spool until it is readyto be pulled as a whole or completed braid arrangement 115 onto a linerlayer 130, 140 of the lead body 50 during the assembly process.

Prior to winding the braid assembly 115, the braid pattern, insidediameter and pitch may be determined according to the type of lead 10being constructed, such as LV, high or low voltage. In some embodiments,the pitch may be varied at certain points along the length of the leadbody 50 to impart different flexibility and torque characteristics atthe certain points along the lead body 50.

Once the braid assembly 115 is braided, the braid assembly 115 may bestored on a large spool. When it is time to assemble a specific leadtubular body 50, the specific length of braid assembly 115 may beremoved from the spool as needed for the specific length of the leadtubular body 50 being assembled. This specific length of braid assembly115 may then be pulled over an innermost liner layer 130, which, asdiscussed above, may be PTFE or other applicable polymer materials. Oncethe braid assembly 115 extends about the outer circumferential surface215 of the innermost liner layer 130, SPC (which is also known as OPTIM™and will act as the wall material 162) may be reflowed or molded (e.g.,LIM) about the braid assembly 115 and innermost liner layer 130 enclosedwithin the braid assembly 115. Specifically, in one embodiment employingreflowing, a SPC tube 162 may be pulled over the combined braid assembly115 and liner layer 130. A fluorinated ethylene propylene (“FEP”) jacketis then pulled over the SPC tube 162, the braid 115, and liner 130 andthen subjected to reflow conditions to form the inner layer assembly155. The FEP jacket is then removed from the resulting inner layerassembly 155.

In some embodiments, a mandrel is used to dip or extrude the PTFE liner130 onto the mandrel outer circumferential surface. The PTFE innermostliner layer 130 is left on the mandrel as the braid 115 is braided overthe outer circumferential surface 215 of the innermost liner layer 130.The SPC wall material 162 is then reflowed or molded over the PTFE linerlayer 130 and braid 115, imbedding the braid 115 in the wall material162. The mandrel can then be pulled from the completed assembly or leftin the completed assembly for the addition of additional elements of thelead. The completed assembly can be stored on a spool in lengths of, forexample, 500′ or discrete lengths.

In multi-layer leads, the inner layer may be built as described abovewith respect to the mandrel process and stored on a spool or in discretelengths, the mandrel for the inner layer being of a small diameter. Asecond or outer layer may then be assembled as described above withrespect to the mandrel process, except the second mandrel is of a largerdiameter as compared to the first mandrel. Once the second layer (i.e.,outer layer) is completed, it may be pulled over the first layer (i.e.,inner layer).

In some embodiments, the inner layer is assembled via any of the abovedescribed methods, and the outer layer assembly takes place by firstpulling an outer PTFE layer over the assembled inner layer. The outerbraid is then braided over the outer PTFE layer. The SPC wall materialfor the outer layer is then reflowed or molded over the outer braid andouter PTFE layer.

In one embodiment, the inner layer is a standard inner lead layerhaving, for example, a helical inner conductor coil surrounded by a PTFEliner. An outer layer with the imbedded braid, as described herein,could be pulled over the standard inner layer or assembled over thestandard inner layer via any of the above-described methods.

At this point in the process, the conductor 100 may be laser ablated toexpose the conductor 100 through the conductor insulation, if any, andthe reflowed SPC wall material 162 to create a pathway that may be usedto electrically couple the conductor 100 to the anchor electrode 85. Acrimp slug may be applied to the exposed conductor 100 in preparationfor electrically connecting the conductor 100 and electrode 85.

The shank 225 and its connected helical anchor electrode 85 may beinserted into the distal end of the inner layer assembly 155 andconnected thereto. The crimp slug may then be laser welded to thehelical anchor electrode 85 or the shank 225, which is electricallyconnected to the helical anchor electrode 85.

Generally speaking, a crimp slug may be attached to a conductor beforeor after the conductor insulation, if any, is removed. The form of acrimp slug may be open or closed, tubular or coiled, and/or circular. Aconductor may be cut or left intact depending on the type of crimp slugused. This process may be repeated as many times as needed to attach theappropriate number of electrodes. Depending on where the electrode islocated, the electrode may be a platinum band/ring, a half ring, aquarter ring, a coil, a helical active fixation anchor, and/or a sensor.The electrode may be attached to the crimp slug via laser welding.

After the electrode 85 has been attached to the crimp slug, any gapsaround and under the electrode 85 are filled in with the appropriatematerial such as, OPTIM™, MedA, epoxy, etc. The proximal end of theconductor 100 and inner layer assembly 155 may then be coupled torespectively to the pin contact 55 and lead connector end 35.

Once the inner layer assembly 155 is completed, the construction of theouter layer assembly 160 may be begun. As with the inner layer assembly155, the specific length of braid assembly 115 may be removed from thespool. This specific length of braid assembly 115 may then be pulledover an outermost liner layer 140, which, as discussed above, may bePTFE or other applicable polymer materials. Once the braid assembly 115extends about the outer circumferential surface 195 of the outermostliner layer 140, SPC (which is also known as OPTIM™ and will act as thewall material 162) may be reflowed or molded (e.g., LIM) about the braidassembly 115 and outermost liner layer 140 enclosed within the braidassembly 115. Specifically, in one embodiment employing reflow, a SPCtube 162 may be pulled over the combined braid assembly 115 and linerlayer 140. A FEP jacket is then pulled over the SPC tube 162, the braid115, and liner 140 and then subjected to reflow conditions to form theouter layer assembly 160. The FEP jacket is then removed from theresulting outer layer assembly 160.

At this point in the process, the conductors 105, 110 may be laserablated to expose the conductors 105, 110 through the conductorinsulation, if any, and the reflowed SPC wall material 162 to create apathway that may be used to electrically couple the conductors 105, 110to the respective electrodes 80, 82. Crimp slugs may be applied to theexposed conductors 105, 110 in preparation for electrically connectingthe conductors 105, 110 to their respective electrodes 80, 82.

As can be understood from FIGS. 3 and 8, where the lead employs a shockcoil 82 and may be a high voltage lead, the conductive path to the shockcoil 82 may include multiple conductors 110 that, when combined, meetthe electrical requirements for shocking while the lead body 50 stilloffers a reduced diameter on account of the configuration of the braidassembly 115 employed in the outer layer assembly 160. Silicone, SPC orother materials may be added to the coil 82 to stabilize the coil 82 andcreate a non-tissue in-growth (“NTI”) surface on the coil 82. The areaadjacent the electrodes 80, 82 may be filled in with a reflowed ormolded SPC or other material to create an isodiametric lead body 50.

In some embodiments, once the entire lead body is constructed via any ofthe above described methods, the entire lead body or portions thereofmay be heat-set to assume a desired configuration that may, for example,allow passive fixation features to bias within a vein for LVimplantation in the case of a CRT lead. Also, such heat-setting may beused for strain relief.

At this point, in one embodiment, the outer layer assembly 160 is pulledover the completed inner layer assembly 155 such that the outercircumferential surface 205 of the inner layer assembly 155 abutsagainst the inner circumferential surface 200 of the outer layerassembly 160. The crimp slugs of the respective conductors 105, 110 maythen be laser welded to the respective electrodes 80, 82. After theelectrodes 80, 82 have been attached to the crimp slugs, any gaps aroundand under the electrodes 80, 82 are filled in with the appropriatematerial such as, OPTIM™, MedA, epoxy, etc. The proximal end of theconductors 105, 110 and outer layer assembly 160 may then be coupledrespectively to the ring contacts 60, 61 and lead connector end 35. Inone embodiment, the resulting completed lead 10 may have a tubular body50 with an braid-reinforced inner layer assembly 155 that is axiallyrotatable relative to an braid-reinforced outer layer assembly 160,thereby allowing the inner layer assembly 155 to be rotated via the pincontact 55 to cause the helical anchor electrode 85 to extend or retractat the lead distal end 70.

When the lead body 50 is manufactured on a continuous basis, theappropriate length of inner liner 130 may be selected depending on thetype of lead 10 being constructed. The braid assembly 115 may then bebraided over the outer circumferential surface 215 of the inner liner130 in a continuous manner. If beneficial to the lead configuration andfunction, a variable pitch may be braided into the braid assembly 115where desired during the braiding process. Once the braid assembly 115is braided over the inner liner 130, the SPC wall material 162, crimpslugs, shank 225, anchor 85 and electrical connections may be completedas discussed above with respect to the individual basis discussion,thereby forming the inner layer assembly 155.

A braid assembly 115 is then braided onto the outer circumferentialsurface 195 of the outer liner layer 140. Once the braid assembly 115 isbraided over the outer liner 140, the SPC wall material 162, crimpslugs, shank 225, anchor 85 and electrical connections may be completedas discussed above with respect to the individual basis discussion,thereby forming the outer layer assembly 160. The inner layer assembly155 is then placed within the outer layer assembly 160 as discussedabove with respect to the individual basis discussion, thereby formingthe complete lead body 50. In one embodiment, the resulting lead body 50has an inner braid-reinforced layer assembly 155 that is axiallyrotatable within an outer braid-reinforced layer assembly 160 to cause ahelical anchor electrode 85 to extend/retract from the lead distal tip.

In some embodiments, the braid assembly 115 of the outer layer assembly160 may be left exposed in certain selected discrete areas along thelength of the lead body 50. These discrete areas of exposed braidassembly 115 may function as tissue in-growth locations where tissue mayin-grow into the exposed braid assembly to facilitate chronic anchoringof the lead body 50 at the location of the implantation of the lead 10.

In some embodiments, one or more of the conductors 105 may instead be atubular lumen extending distally from the lead proximal end. Such alumen or lumens 105, although forming a portion of the braid assembly115, may be used to transfer something other than current through thelead body 50. For example, such a lumen 105 of the braid assembly 115may be used to deliver air, liquid, drugs, etc. from a proximal end ofthe lead to a location on the lead near the lead distal end.

In some embodiments, the helix anchor 85 at the lead distal end is notextendable/retractable relative to the lead distal end. Instead, thehelix anchor 85 is fixed in an extended configuration and the entirelead body is rotated to imbedded the helix anchor 85 in cardiac tissue.Thus, in such fixed helix anchor embodiments, the inner layer of thelead body is not configured to rotate within the outer layer of the leadbody or, alternatively, the lead body has a single layer.

The braid-reinforced layer assemblies 155, 160 used to form the leadtubular body 50 offer a number of advantages over known lead bodyconfigurations. For example, in some embodiments, the suchbraid-reinforced layer assemblies 155 may be substituted for helicallywound central coils that are employed to extend/retract helical anchors;providing one-to-one torqueability, reduced manufacturing costs, andimproved and more consistent flexibility as compared to leads employingthe helically wound central coils known in the art.

The braid-reinforced layer assemblies 155, 160 allow greater flexibilityin positioning an electrode along the lead body as the conductors of theassemblies 155, 160 are more readily located and accessible, as comparedto lead configurations known in the art. As a result, the manufacturingof multi-electrode leads having, for example, 1-32 or more electrodes ismade more feasible.

Since the conductors are imbedded in the material of the tubular wall,the French size made possible via the braid-reinforced layer assemblies155, 160 may be substantially less than other leads commonly known inthe art.

The leads disclosed herein are applicable to both cardiologyapplications and other medical areas, including neurological.

For a discussion regarding crimp slug configurations that can securelycoupled to a variety of types of electrical conductors used in leads,including the helically wound conductors 100, 105, 110 of theabove-described braided layers, reference is first made to FIGS.11A-11C. FIG. 11A is an isometric view of a zip tie type crimp slug 300.FIGS. 11B and 11C are, respectively, plan and side views of the crimpslug 300 of FIG. 11A.

As shown in FIGS. 11A-11C, in one embodiment, the crimp slug 300includes a ribbon or tail 305 and a collar 310. The tail 305 has asubstantial length as compared to the size of the collar 310, extendsfrom the collar 310 on one end, and terminates on the other end in theform of a tip or free end 315. The collar 310 includes a hole 320defined therein and extends relative to the tail 305 such that the faces325 of the collar 310 are generally transverse to the tail 310.

In one embodiment, the tail 305 includes an inner face 330 that is agenerally flush extension of the arcuate inner surface 335 of the hole320 and is similarly arcuate. The tail 305 includes an outer face 340that is a generally flush extension of the arcuate outer surface 345 ofthe collar 310 and is similarly arcuate.

In one embodiment, the tail 305 extends between approximately 0.05″ andapproximately 0.5″ from the adjacent collar face 325. The tail 305 has atransverse width of between approximately 0.005″ and approximately0.02″. The tail 305 has a thickness of between approximately 0.001″ andapproximately 0.008″. The collar 310 has an outer diameter of betweenapproximately 0.01″ and approximately 0.04″. The collar 310 has a faceto face thickness of between approximately 0.002″ and approximately0.01″. The hole 320 has a diameter of between approximately 0.005″ andapproximately 0.02″. The crimp slug 300 is formed of an electricallyconductive material, such as, for example, platinum-iridium alloy,platinum, MP35N, or etc.

The crimp slug 300 depicted in FIGS. 11A-11C is advantageouslyconfigured such that it may be attached to a cable or a solid filamentrouted in either a wound or straight configuration. Even moreadvantageously, the crimp slug 300 can be coupled to such a cable orsolid filament imbedded in a polymer (e.g., SPC) and only exposed in aspecific region, as may be the case with conductors 100, 105, 110 of theembodiments of the lead body described above with respect to FIGS. 1-10.

For a discussion of a method of preparing the lead body 50 for thecoupling of the crimp slug 300 of FIGS. 11A-11C to a conductor 100 inthe lead body, reference is made to FIGS. 12A-12C. FIG. 12A is a planview of a portion of a lead tubular body 50 with a conductor 100helically routed about a liner layer 130 and imbedded in the polymermaterial 162, the helically routed conductor 100 and polymer material162 forming the reinforced layer 135. FIGS. 12B and 12C are,respectively, cross sections of the lead tubular body 50 as taken alongsection line 12B-12B and section line 12C-12C in FIG. 12A.

As shown in FIGS. 12A-12C, the polymer material 162 of the reinforcedlayer 135 is removed in the vicinity of a desired conductor accesslocation to form a recessed ring 350 about the outer circumference ofthe tubular body 50 and a window 355 in the recessed ring 350 thatextends in general alignment with the helically wound conductor 100revealed by the window 355. The removal of the polymer material 162 maybe accomplished via a variety of methods, including, for example, laserablation. The ablation or other removal method may also be used toremove any electrical jacket that may be present about the conductor100, thereby reveal the electrically conductive core of the conductor100, as shown in FIGS. 12A-12C.

In one embodiment, the polymer material 162 may be masked during reflowto result in voids or openings that may be used to access the conductorsor allow for the addition of conductive elements to the conductors.

FIG. 13A is a view of the tubular body 50 similar to the view depictedin FIG. 12A and illustrating the beginning of the process of couplingthe crimp slug 300 to the conductor 100 exposed in the window 355.Specifically, as shown in FIG. 13A, the tail 305 of the crimp 300 isinserted under the exposed conductor 100 by working the tip 315 of thecrimp tail 305 under the conductor 100 and then further sliding thecrimp tail 305 under the conductor 100 to cause the crimp collar 310 tomove towards the conductor 100. As shown in FIG. 13B, which is generallythe same view of the tubular body 50 depicted in FIG. 13A, the crimptail tip 315, which is wrapped around the exposed conductor 100, isinserted through the crimp collar hole 320. The crimp 300 now forms aloop 360 about the exposed conductor 100. The crimp tail tip 315 isgrasped (e.g., via a crimp tool) and pulled as the crimp collar 310pushed down against the cable, cinching the crimp tail 305 down tight onthe conductor 100. The crimp collar 310 can then be crimped down on thecinched tight tail 305 to hold the tail 305 tightly cinched about theconductor 100, as shown in FIG. 13C-13E. A final crimp of the collar maybe applied to further lock the collar in position about the tightlycinched tail.

Once the crimp 300 is fully cinched down on the conductor 100 and fullycrimped to lock the crimp 300 in place, a ring electrode 80 may bepositioned on the lead body and coupled to the crimp 300. For example,as depicted in FIG. 14A, which is an isometric of a split ring electrode80, an electrode 80 configured to be coupled to the crimp 300 may havean overall ring shape that includes a cylindrical wall 390 with an outercircumferential surface 400, an inner circumferential surface 405, anfirst end edge 410, a second end edge 415, and a slot, cut or split 420extending through the wall 390 generally parallel to the axis of theelectrode 80. The slot 420 is defined by opposed edges 425. Each opposededge 425 includes a notch 430.

The ring electrode 80, when in an expanded or split condition as shownin FIG. 14A with the opposed edges 425 spaced apart from each other, hasan inner diameter that is greater than the outer diameter of the leadbody 50. Thus, when the ring electrode 80 is in the split conditionshown in FIG. 14A, the lead tubular body 50 can be threaded through thering electrode to cause the ring electrode to be positioned over therecessed ring 350 formed in the lead body (see FIG. 13C), the notches430 being positioned on each side of the crimp 300. As shown in FIG.14B, which is a view of the lead tubular body similar to that of FIG.13B, the ring electrode 80 can then be transitioned to a contracted ornon-split condition by pressing the opposed edges 425 of the ringelectrode together such that the inner diameter of the ring electrodematches the outer diameter of the lead tubular body 50 at the recessedring 350 and the outer diameter of the ring electrode 80 matches theouter diameter of the lead tubular body proximal and distal of therecessed ring 350. Thus, the ring electrode 80 in the non-splitcondition resides with the recessed ring 350 in the tubular body 50 andthe outer circumferential surface 400 of the ring electrode 80 isgenerally flush with the outer circumferential surface of the lead body50.

As indicated in FIG. 14B, when the ring electrode is positioned in therecessed ring 350 in a non-expanded condition with the opposed edges 425abutting or nearly abutting each other and the crimp 300 is locatedbetween the notches 430, the notches 430 form a window or opening 435 inthe wall of the ring electrode 80 through which the crimp 300 extends.As illustrated in FIG. 14C, a weld 440 can be formed at the location ofthe crimp and window to mechanically and electrically couple the crimpto the ring electrode and maintain the ring electrode in thenon-expanded condition. Additional welds can be formed along the opposededges 425 is it is desired to close off the seam formed by the opposededges 425. It should be note that although in some embodiments the crimp300 projects into the window 435, in other embodiments this may not bethe case, the window simply serving for visualization during welding,the crimp simply being located below the window, but not projecting intothe window.

The split ring electrode 80 of FIGS. 14A-14C combined with an ablatedrecessed ring in the lead body provides a novel way of creating anisodiametric lead body. While the split ring electrode works well withthe ribbon type crimps discussed above, the split ring electrode can beused to attach to an assortment of more traditional crimps. Thepreferred configuration is to have a ribbon/post come through the splitcrimp window. However, the window can also just be used forvisualization during welding, allowing the concept to be used inconjunction with almost any crimp currently used in the industry.

Other ring electrode configurations may be employed with the crimp 300For example, as depicted in FIG. 15A, which is an isometric of a notchedring electrode 80, an electrode 80 configured to be coupled to the crimp300 may have an overall ring shape that includes a cylindrical wall 390with an outer circumferential surface 400, an inner circumferentialsurface 405, an first end edge 410, a second end edge 415, and a notch445 extending through the wall 390 oblique to the axis of the electrode80. The notch 445 is defined in one of the end edges 410 and extend inthe direction of the opposite edge for a portion of the length of thering electrode.

As shown in FIG. 15B, which is a view of the tubular body 50 similar tothat of FIG. 14B, the ring electrode of FIG. 15A may be supported on thetubular body with the notch 445 positioned such that the crimp 300 islocated within the notch 445. The notch 445 and crimp 300 can be weldedtogether to form a weld similar to that discussed above with respect toFIG. 14C.

For a discussion regarding another crimp slug configuration, referenceis now made to FIGS. 16A-16D. FIG. 16A is a plan view of another zip tietype crimp slug 300 in a flat pattern state. FIG. 16B is an isometricview of the zip tie type crimp slug 300 of FIG. 16A in a formedcondition. FIGS. 16C and 16D are, respectively, isometric and side viewsof the crimp slug 300 of FIG. 16B in a looped state.

As shown in FIGS. 16A-16B, in one embodiment, the crimp slug 300includes a ribbon or tail 305 and a slot head 480. The tail 305 has asubstantial length as compared to the size of the slot head 480, extendsfrom the slot head 480 on one end, and terminates on the other end inthe form of a tip or free end 315. The slot head includes a slot 485defined therein, the slot 485 extending transverse to the tail 310.

As shown in FIGS. 16B-16D, the slot head 480 includes two opposedhalf-cylinder portions 490, each half-cylinder portion 490 sharing acommon longitudinal merged or joined wall portion 495 and each having afree longitudinal wall edge 500. The tail 305 extends from free walledge 500 of one of the half-cylinder portions 490, and the slot 485 isdefined in the center of the trough of the other half-cylinder portion490. The slot 485 extends generally parallel to the longitudinal axis ofthe half-cylinder portion 490 in which the slot is defined. Since thehalf-cylinder portions 490 are opposed and share a common wall portion495, the slot head 480 has a s-shaped side edges, as can be understoodfrom FIGS. 16B-16D.

In one embodiment, the tail 305 includes an inner face 330 that is agenerally flush extension of the arcuate inner surface of the trough ofthe half-cylindrical portion 490 from which the tail extends. The tail305 includes an outer face 340 that is a generally flush extension ofthe arcuate outer surface of the half-cylindrical portion 490 from whichthe tail extends.

In one embodiment, the tail 305 extends between approximately 0.1″ andapproximately 0.5″ from the free wall edge 500 from which the tailextends. The tail 305 has a transverse width of between approximately0.005″ and approximately 0.02″. The tail 305 has a thickness of betweenapproximately 0.002″ and approximately 0.01″. Each half-cylinder portion490 has an outer diameter of between approximately 0.01″ andapproximately 0.04″. Each half-cylinder portion 490 has an innerdiameter of between approximately 0.003″ and approximately 0.02″. Theslot head 480 has a length of between approximately 0.01″ andapproximately 0.1″. The slot 485 has a width of between approximately0.002″ and approximately 0.012″ and a length of between approximately0.005″ and approximately 0.025″. The crimp slug 300 is formed of anelectrically conductive material, such as, for example, platinum-iridiumalloy, platinum, MP35N, or etc.

The crimp slug 300 depicted in FIGS. 16A-16D offers the same advantagesof the crimp 300 depicted in FIGS. 11A-11C. Also, as can be understoodfrom a comparison of the FIG. 16C to FIG. 13C, the crimp slug 300 ofFIGS. 16A-16D may be secured to the conductor 100 and a ring electrode80 in the same manner as the crimp slug 300 in FIGS. 11A-15B.Specifically, the tail 305 is looped around the conductor 100, threadedthrough the slot 485, and then cinched tight about the conductor 100.The slot head 480 is then crimped down on the tail to maintain the crimpslug 300 tightly cinched down on the conductor. The ring electrode canthen be placed about the lead tubular body and welded to the crimp slug.

In one embodiment, as shown in FIGS. 17A and 17B, which are,respectively, isometric and plan views of a lead body, the crimp slug300 is in the form of a ribbon or strip 520 that is inserted under theexposed conductor 100, the free ends 525 of the ribbon 520 being broughttogether and pulled such that the ribbon 520 is wrapped tightly aboutthe exposed conductor 100. Specifically, the ribbon doubles back onitself and slides in to a slot 445 in the notched ring electrode 80 ofFIG. 15A or a window 435 of the split ring electrode 80 of FIG. 14A. Ahalf-cylinder shaped tool 535 having an arcuate inner surface that hasdiameter that generally matches the outer diameter of the lead body maybe employed to crimp the ribbon about the conductor 100. The tool 535may have a slot or notch 535 similar, but opposite to the slot or notch445 in the ring electrode 80. Pulling on the ribbon free ends 525 andpushing with the tool 530 can cinch and crimp the ribbon 520 tightlydown on the conductor 100. The ribbon can then be spot welded within thering electrode notch 445.

The ribbon is formed of an electrically conductive material similar tothat discussed above with respect to FIGS. 11A-11C and 16A-16D and mayhave dimensions similar to those discussed above with respect to thetail 305.

The embodiments of the crimp 300 discussed above with respect to FIGS.11A-17B may be considered to have a tail portion (alternatively referredto as a ribbon portion) that can be slid under a conductor 100 imbeddedin a layer of the lead body. These crimps can be constructed from a flatpattern or a tube and can take on many different configurations whilestill achieving the same general crimp concept. Also, any of these tailor ribbon equipped crimps 300 of FIGS. 11A-17B can be attached to two ormore conductors 100 running next to each other (e.g., for the purposesof redundancy).

In one embodiment, as depicted in FIG. 17C, which is a transverse crosssection of the lead body 50 at a location of an alternative version ofthe ribbon equipped crimp 300 of FIGS. 17A-17B, the crimp 300 mayinclude a collar 310 that is separate from the ribbon portion 525 of thecrimp 300. Once the ribbon portion 525 is tightly wrapped about theconductor 100, the collar 310 can be slid down over the ribbon portion525 and then crimped down on the ribbon portion 525. The ring electrode350 can then be placed over the collar 310 such that the ribbon portion525 extends from opening (e.g., slot) in the ring electrode and thecollar 310 is in intimate contact with the inner surface of the ringelectrode. The ribbon portion and collar can then be welded to the ringelectrode.

The process of wrapping the ribbon portion around the conductor 100,cinching the crimp tight, and crimping, results in mechanicallydeformation between the crimp and the conductor. This ensures a reliableelectrical and mechanical connection between the conductor and thecrimp, which is then welded or otherwise mechanically and electricallycoupled to the ring electrode.

These crimps 300 may be employed to couple conductors 100 to ringelectrodes 80 that are in the form of split-ring electrodes, solid ringelectrodes, half-ring electrodes, etc. These crimps 300 can also be usedto couple the conductors 100 to shock coils 82 in the form of spot endor solid ring end shock coils. Finally, these crimps 300 can be used tocoupled conductors 100 to additional features, such as, for example,sensors or chips.

These crimps 300 are particular useful when attaching to a straight orwound conductor 100 when the ends of the conductor are constrained orlocked into a polymer matrix of a lead body. The ribbon equipped crimps300 are particularly well suited for attachment to a wound conductor 100because only a narrow ribbon 305 can be slid under the imbeddedconductor 100. Also, the ribbon 305 facilitates the easy and securecoupling of the crimp to a helically routed conductor.

FIG. 18A is an isometric view of another embodiment of the crimp slug30. As shown in FIG. 18A, the crimp 300 includes a tail 590 extendingfrom a cylindrical head 600. The cylindrical head 600 includes alongitudinal slot 605 and a transverse slot 610. The longitudinal slot605 is generally parallel to the longitudinal axis of the cylindricalhead 600 and defines two longitudinal edges 615 in the wall of the head600. The tail 590 extends from one of the edges 615, and the transverseslot 610 begins at the other edge 615. The tail 590 and transverse slot610 are centered on the head 600 with respect to the length of the head.

As illustrated in FIG. 18A, the exposed conductor 100 is received in thetrough of the cylindrical head 600. Specifically, the edge 615 in whichthe transverse slot 610 is defined is inserted under the exposedconductor 100 to cause the conductor to be received in the trough of thehead 600.

As indicated in FIGS. 18B and 18C, which are, respectively, top andbottom isometric views of a half-cylinder shaped tool 535 for use incrimping the crimp 300 on an exposed conductor 100, the tool 535 has anarcuate inner surface 630 that has diameter that generally matches theouter diameter of the lead body. A helically routed groove or recess 635is defined in the arcuate inner surface 630. An opening 640 extendsthrough the wall 645 of the tool 535 from the recess 635. The tail 590of the crimp 300 extends through the opening 640 when the cylindricalhead 600 of the crimp 300 is received in the opening 640.

Pulling on the tail and pushing with the tool 530 can cinch and crimpthe ribbon cylindrical head 600 tightly down on the conductor 100. Thetail 590 can then be spot welded within the ring electrode notch 445 orwindow 435.

In one embodiment, the tail 590 extends between approximately 0.01″ andapproximately 0.2″ from the edge 615 from which the tail extends. Thetail 590 has a transverse width of between approximately 0.002″ andapproximately 0.02″. The tail 590 has a thickness of betweenapproximately 0.002″ and approximately 0.01″. The cylinder head 600 hasan outer diameter of between approximately 0.012″ and approximately0.03″. The cylinder head 600 has an inner diameter of betweenapproximately 0.004″ and approximately 0.015″. The cylinder head 600 hasa length of between approximately 0.02″ and approximately 0.1″. Thelongitudinal slot 605 has a width of between approximately 0.003″ andapproximately 0.02″ and a length of between approximately 0.02″ andapproximately 0.1″. The transverse slot 610 has a width of betweenapproximately 0.003″ and approximately 0.022″ and a length of betweenapproximately 0.01″ and approximately 0.04″. The crimp slug 300 isformed of an electrically conductive material, such as, for example,platinum-iridium alloy, platinum, MP35N, or etc.

FIG. 19 is an isometric view of a side loader crimp slug 300. Asdepicted in FIG. 19, the crimp 300 includes a cylindrical head 675 witha longitudinal slot 680 that defines two opposed edges 685. One edge 685includes two end projections 690 separated by a single central recess695. The other edge 685 includes a single centered projection 700. Thetwo edges complement each other in that when the edges 685 are forcedtogether when the crimp 300 is crimped down on an exposed conductor 100extending through the cylindrical head 675, the single centeredprojection 700 is received in the single central recess 695, and the endprojections 690 are received in the open spaces 705 adjacent thecentered projection 700.

As illustrated in FIG. 19, the exposed conductor 100 is received in thetrough of the cylindrical head 675. Specifically, one of the edges 685is inserted under the exposed conductor 100 to cause the conductor to bereceived in the trough of the head 675.

The crimp 300 could be added to the conductor before the conductor iswound into the lead body as described above with respect to FIGS. 1-10.A hole 710 in the crimp 300 could then be used to add a post to thecrimp. The post could be added by stamping a flat pattern and weldingthe post into the hole.

Alternatively, the crimp 300 could be made as shown and then crimpedonto the conductor subsequent to the conductor being wound into the bodyas described above with respect to FIGS. 1-10. After crimping a postcould be placed in the hole and welded on. This post, similar to thetails described a above, would be used to aid in welding and alignmentto a slot or window in the ring electrode.

In other embodiments, the crimp 300 will not have the hole 710 depictedin FIG. 19. The crimp is instead welded to the ring electrode viawelding and direct intimate contact between the outer surface of thecrimp and the interior of the ring electrode.

FIGS. 20A and 20B, which are, respectively, isometric and side views ofanother crimp slug 300. As shown in FIGS. 20A and 20B, the crimp slug300 includes a generally cylindrical side surface 730, a planar uppersurface 732, and a semi-sloped bottom surface 735. A pair of notches orrecesses 740 are defined in opposite sides of the cylindrical sidesurface 730, the recesses being configured to be engaged by a crimpingtool. A notch or recess 745 is defined in the bottom surface 735, therecess being configured to receive a conductor 100.

FIG. 20C is a side view of a portion of a lead body 50, wherein thecrimp slug 300 of FIGS. 20A and 20B is coupled to a conductor 100. Asdepicted in FIG. 20C, the conductor 100 is received in the bottom recess745, and a crimp tool is applied to the side recesses 740 to crimp thebottom recess 745, causing the crimp slug 300 to be coupled to theconductor 100. The crimp slug 300 can be attached to a pre-woundconductor, access to the conductor 100 being achieved by ablating awindow. Alternatively, the crimp slug 300 can be added to the conductor100 prior to the addition of the polymer layer in which the conductorends up being imbedded. Regardless of when the crimp slug 300 isattached to the conductor, the crimp can then be welded to a split ringelectrode or a slotted ring electrode.

FIGS. 21A and 21B, which are, respectively, isometric and side views ofanother crimp slug 300. As illustrated in FIGS. 21A and 21B, the crimpslug 300 includes a generally spherical outer surface 750 and a notch orrecess 755 defined in the spherical outer surface 750, the recess beingconfigured to receive a conductor 100.

Similar to the crimp 300 of FIGS. 20A-20C, the crimp 300 of FIGS.21A-21B can be coupled to a conductor 100. Specifically, the conductor100 is received in the recess 755, and a crimp tool is applied to theouter spherical surface 750 to crimp the recess 755, causing the crimpslug 300 to be coupled to the conductor 100. The crimp slug 300 can beattached to a pre-wound conductor, access to the conductor 100 beingachieved by ablating a window. Alternatively, the crimp slug 300 can beadded to the conductor 100 prior to the addition of the polymer layer inwhich the conductor ends up being imbedded. Regardless of when the crimpslug 300 is attached to the conductor, the crimp can then be welded to asplit ring electrode or a slotted ring electrode.

As indicated in FIG. 22, which is a plan view of a twisted crimp 300 ona conductor 100, the crimp slug 300 may be in the form of a micro wireor coil 760 twisted onto the conductor 100 and then crimped flat on theconductor. The twisted crimp 300 can then be welded to a ring electrode80.

Most, if not all, of the above-described crimp slugs 300 can be added tothe conductor 100 subsequent to the assembly of the conductor into thelead body 50. Also, most, if not all, of the above-described crimp slugs300 can be added to the conductor 100 prior to the conductor 100 beingassembled into the lead body 10, for example, where the crimp slugs 300are applied to the conductor 100 and the crimp slug equipped conductoris stored in discrete lengths or in bulk on a spool until needed forassembly into the lead body 50. Also, in another embodiment, the crimpslugs 300 may be added to the conductor 100 during the manufacture ofthe lead body 50 immediately before the conductor 100 is wound into thelead body.

The following crimp slugs 300 are especially useful in the context ofapplying the crimp slugs 300 to a conductor 100 prior to the conductor100 being assembled into the lead body 50. Specifically, the crimps 300discussed below are attached to the conductor 100 and the crimp equippedconductor 100 is stored in discrete lengths or in bulk on spools untilneeded for assembly into a lead body. For example, when assembling thelead body 50 depicted in FIG. 4, a conductor 100 with crimps 300 alreadymounted along the length of the conductor 100 is removed from a spooland wound about the inner liner 130.

As can be understood from FIGS. 23A and 23B, which are, respectively, aside view of a lead body 50 and an enlarged side view of the same leadbody at a location of a crimp 300, in the context of preassembling thecrimps 300 onto the conductor 100 and storing the conductor in discretelengths or on a spool, the crimps 300 can be added at a evenly spaceddefined distance on a conductor 100. The spacing of the crimps 300 onthe conductors 100 could be such that when multiple conductors are woundonto the liner 130, the crimp patterns are appropriately offset tocreate a specified spacing between the crimps. For example, as indicatedin FIG. 23A, four conductors 100, 105, 110, 111 are wound about theliner 130 and the crimps 300 on the conductors are spaced such that thespacing X between adjacent crimps 300 is approximately 15 mm apart, thepattern repeating approximately every 90 cm.

FIGS. 24A and 24B are, respectively, a plan view of a helical woundcrimp 300 and a plan view of the same crimp 300 mounted on a conductor100. As indicated in FIGS. 24A and 24B, such a helical wound crimp 300may have coils 800 with a variable pitch. Specifically, part of thecrimp 300 has a tight pitch region 805 that can act as a strong locationfor welding to a ring electrode and an open pitch region 810 that canact as a conformal strain relief. In one embodiment, the coils 800 ofthe tight pitch region 805 is welded to the ring electrode 80. Inanother embodiment, a portion of the crimp 300 is welded to the ringelectrode 80, wherein the portion of the crimp 300 is a coil 800 that ispulled outward to form a tab to be welded to the electrode or an end ofthe wire forming the coils 80 is pulled outward to form a table to bewelded to the electrode. The resulting tab could be welded to the slotin the ring electrode, similar to methods described above.

To mount the helical crimp 300 on the conductor 100, the conductor isthreaded through the helical crimp 300 when the helical crimp is in acylindrical shape. Once positioned as desired, the helical crimp 300 iscrimped onto the conductor 100 to cause the crimp to conform to theconductor.

FIGS. 25A-25C illustrate, respectively, side, inner and outer views of ahelically shaped crimp 300. As can be understood from FIGS. 25A-25C, thecrimp 300 is a solid tube that is helically shaped. The helical crimp300 of FIGS. 25A-25C would work similar to the helical spring crimp 300of FIGS. 24A-24B. Specifically, as can be understood from FIGS. 25D-25E,which are, respectively, the crimp 300 on a conductor and acrimp-equipped conductor assembled into a lead body, the conductor 100would be fed through the helical crimp 300. The crimp 300 would then becrimped onto the conductor 100 such that the crimp 100 would match thenatural pitch of the final wound cable. The helical crimp outsidediameter would match the inside diameter of the ring electrode 80,creating a large surface for welding. The crimp 300 would be welded to aring electrode 80 through a hole 815 for visualization in the crimp 300.

All crimp concepts disclosed herein apply to conductors that are solidwire or multi-filar conductors and conductors that are wound or braided.

Although the present invention has been described with reference topreferred embodiments, persons skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention.

What is claimed is:
 1. An implantable medical lead comprising: alongitudinally extending body having a distal end and a proximal end; anelectrode on the body near the distal end; a lead connector end operablycoupled to the proximal end of the body; a tubular braid arrangementhaving an electrical conductor braided with an electrical nonconductor;wherein the electrical conductor extends between the lead connector endand the electrode; and a crimp slug comprising a slot head and a tailextending from the slot head, the slot head having a generallyhalf-cylinder shape that defines a trough and the slot head having aslot; wherein the electrical conductor is received in the trough,wherein the tail is looped around the electrical conductor, threadedthrough the slot, and cinched about the electrical conductor, andwherein the slot head is crimped down on the tail to secure theelectrical conductor onto the crimp slug.
 2. The lead of claim 1,wherein the slot extends generally transverse through the slot head. 3.The lead of claim 1, wherein the tail is welded to the electrode to beelectrically and mechanically coupled to the electrode.
 4. The lead ofclaim 1, wherein the electrode comprises a ring electrode with a notchor slot defined therein, a portion of the tail being received in thenotch or slot.
 5. The lead of claim 1, wherein the electrode comprises aring electrode with a split defined therein, the split extending thelength of the ring electrode, the split having notches that define awindow when the split is closed, a portion of the tail being received inthe window.